lasting a very long time, or happening repeatedly or all the time (Cambridge)
continuing for a very long time; happening again and again (Oxford)
بیوقوف ,احمق
We face the perennial problem of not having enough money. (Cambridge).
Colonialism in different forms is a perennial theme of history.(Oxford)
face the perennial problem
a perennial theme of history
Chronic
Persistent
Long-standing
Ceasing
Temporary
Perennially